Pinouts modular legacy board older one..

Pins 1&2 are roller hot, pins 3&4 are ground, pins 5&6 are cab light (AC hot), pins 7&8 are rear coupler, pins 9&10 are rear light hot, pins 11&12 are front coupler AC hot,  pins 13&14 are front light AC hot, pin 15 duty cycle from DCDS (1/02) ,  pin 16 is reverse   PWM, pin 17 Duty cycle (1/01) ,  pin 18 is forward PWM,  pins 19& 20 are +5VDC,  pin 21 not used, pin22 is run/program switch, pin 23 is antenna, and pin 24 is serial data to AC RS/ AC reg.  This is for the R4LC.  If you are looking for all the pins on the motherboard, ask what you are looking for.    The rule of thumb on the R4LC, Railsounds power board, and Railsounds audio board Pins 1&2 are hot (roller) and pins 3&4 are ground.

Before going to Lionel school, we had to know all the pin outs for all the boards in the engine and tender. Diesels also.    If you did not know them, you did not pass the class.  I studied all summer and on the 700 mile trip to Ohio.  At the time it was a monster PITA, now it makes life very easy working on these boards.  

pins are read R-L. 1-23 are bottom row and pins 2-24 are top row.  This is for steam  and diesel.  I hope it helps.  Pin one has a square pad and is located on the bottom row right side looking at the back of the board.

If you're looking for pinouts of the motherboards, Rod Stewart did a few of the TMCC ones a while back, a really nice job.

gunrunnerjohn posted:

If you're looking for pinouts of the motherboards, Rod Stewart did a few of the TMCC ones a while back, a really nice job.

Yes, the motherboard outs - Thanks, Marty - I already have that information.  I'm 

In the process of repairing item # 6-11117 legacy atlantic.  Waiting for a new encoder ring. One wire popped off a connector. It look like the brown wire from the serial comm smoke unit regulator. I will have to meter out the motherboard.

Let me know if I can be any help, I have all you are looking for in my Lionel information.  The serial on the reg is the brown wire.  you are correct.